HTTPS Everywhere aims to have a simpler user experience than NoScript, and to support complex rewriting rules that allow services like Google Search and Wikipedia to be redirected to HTTPS without breaking anything.

Difference is HTTPS everywhere will use HTTPS when it is available, NOSCRIPT says only use HTTPS period. So it appears to me if the site doesn't have HTTPS you wouldn't be able to view it with NOSCRIPT. You can however whitelist from site to site of course this is a bit cumbersome.

I use both at times, but my favorite tool for this job is HTTPS Finder. It probes the sites you visit for HTTPS support, and can swap you over whenever HTTPS is available. It can also write the HTTPS Everywhere rules for you.